Plan Your Grabber's New Design
The questions on this page have students think about their design for the new Grabber, the plan for creating it, and the benefits of the modification. This activity is less about perfecting the Grabber build and more about getting students to decompose the problem of improving it, consider techniques for improving it, plan out a way to change it, and explain or justify why this proposed change is worthwhile. That should all be included within their engineering notebooks. Click either for an individual engineering notebook rubric (Google / .docx / .pdf) or a group-based engineering notebook rubric (Google / .docx / .pdf), as is appropriate. Be sure to share the rubric prior to having the students begin answering these prompts.
Answer the following questions in your engineering notebook:
What do you want to change about the build by using other pieces in your VEX Super Kit? Explain at least two changes and name the technique(s) being applied if you are using one of the previous examples.
What parts will you use to change the build? List the names of all needed parts and how many of each part the build requires.
Create your own set of Build Instructions for your new Grabber design so that someone else could follow them to make their own Grabber. Start at Step 1 because the person might not have a Grabber yet. Explain with details and/or sketches.
How do your changes to the Grabber make it better? Explain with details and/or sketches.
Teacher Toolbox - Answers
Students' proposed changes can be as creative as the teacher allows but they should demonstrate consideration for the functionality of the Grabber and the available pieces in the VEX Super Kit. The proposed changes shouldn't simply be aesthetic or idiosyncratic but instead increase the functionality of the Grabber. Also, the proposed changes to the build need to be possible with the parts still available in the VEX Super Kit, after the Grabber is built. Students can communicate their proposals in text or drawings. If students are proposing doubled-up beams, cross-linkages, or off-center pivot points, then be sure they recognize how they are related to the examples provided on the previous page.
Students might start by creating a list of the parts they want to add to the Grabber build, a list of the parts they want to remove, or some smaller list of parts that can start this process. Then they can compile only the parts they need into a single list for their build. It is recommended that students list all of the parts listed, including those that remain from the original Grabber build.
Students should be able to communicate the steps of their changes and the parts used in a logical manner by either text or drawings in their engineering notebook (Google / .docx / .pdf). The build should start at Step 1 and guide a user through building this improved Grabber to completion.
Students should be able to explain why their proposed changes improve the Grabber. Possible explanations could include increasing the Grabber's extension in order to give it a farther reach, reducing the Grabber's extension in order to improve stability and to have the Grabber bend less, improving the Grabber's handles so that users have a better grip, or making the linkages more rigid and strong to properly handle heavier loads/objects.
Extend Your Learning - Carrying out the Building Plans
User-Testing the Build Instructions: If time permits, allow the students to swap build instructions with a classmate. Each student will then follow another's Parts Lists and Build Instructions in an attempt to test how well they plan the build. Students can take notes in their engineering notebooks about which step(s) of the instructions were confusing, if any.
User-Testing the Improved Grabber: Students who are successful in completing the new Grabber build should then test it and compare its strength, rigidity, and extension length to the original Grabber's to determine if it is indeed improved. They can rate each of the three dimensions in their engineering notebooks. An original Grabber might be around so that they can test both versions at the same time.
Documenting User-Feedback: Students can then report back to the designer and find out if the improvements found in testing match the improvements planned. The designer can note whether the new design was successful in reaching its intended improvements to the build.